Rotors for thermal turbomachines such as axial compressors and gas turbines are known in different designs from the comprehensively available prior art. For example, welded rotors are known for gas turbines, in the case of which welded rotors drums of different width are welded to one another to form a monolithic rotor. Secondly, it is known to stack a plurality of disk-shaped elements (also known as rotor disks) and to brace them with the aid of one or more tie rods to form a fixed structure. Even combinations of said designs are known. Rotor blades are mounted on the outside of all rotors, which rotor blades can be assigned in the case of gas turbines, for example, either to the compressor or to the turbine unit. Regardless of the design, a medium can be introduced into the interior of the rotors via holes which are arranged in the rotor shell, in order to conduct said medium from the feed position to a second axial position, where the medium is removed from the rotor again. This method is used, in particular, in gas turbines, in order to remove cooling air from the main flow path of the compressor of a gas turbine on the rotor side and to conduct it to the turbine unit, where, guided out of the rotor interior again, it can be used for cooling air purposes and/or sealing air purposes.
In order to make an aerodynamically efficient removal of air from the compressor of a gas turbine and efficient conducting of the air in the rotor interior possible, different constructions are known.
For example, DE 196 17 539 A1 has disclosed conducting the air which flows with a swirl into the rotor cavity on account of the rotation of the rotor via radially extending ribs to the rotor center. The conducting causes the circumferential speed of the air which exits from the holes to be reduced as the radius becomes smaller, which prevents an impermissibly great swirl formation. For this reason, the ribs are called “deswirlers” in English.